Conventional door frames, especially exterior door frames, are formed from lumber, such as ponderosa pine. These frames have been the industry standard for years, however, as discussed below, require time-, labor- and waste-intensive steps when compared to the invented composite door frame described herein. Furthermore, conventional frames have inherent weaknesses and security concerns on account of their materials of construction.
By way of background, it should be understood that door frames have four principle components. The first two are a pair of elongate jambs, which extend vertically in a side-by-side, opposed relationship to each other to define the side walls of a cavity into which a door is hung. The other two are a header that spans the distance between the upper regions of the jambs to connect the jambs and define the top wall of the cavity, and a sill that spans the distance between the lower regions of the jambs to define the bottom wall of the cavity. Typically, the jambs and header have the same, or substantially the same, cross-sectional configuration. The sill usually is inclined as it extends inwardly from the exterior of the wall within which the frame is installed. A door is "hung" or mounted, via hinges, on one jamb, and includes a lock or clasp that engages a corresponding socket on the other jamb. As used herein, the jamb on which the door is mounted is referred to as the door-side jamb, and the jamb that is engaged by the door's lock or clasp is referred to as the lock-side jamb.
The header and jambs of a conventional frame typically have the cross-sectional configuration shown in FIG. 1. A portion of a jamb is indicated generally at 10 in FIG. 1. As discussed, however, the header and jambs typically have the same cross-sectional configuration. Jamb 10 include a base member 12 that is mounted within an opening in a wall of the building, house or other structure. Base member 12 includes a lower surface 14 that is mounted against the portion of the wall that defines the opening, and exterior and interior surfaces 16 and 18, respectively, that face in the direction of the corresponding exterior and interior surfaces of the wall. As discussed, base member 12 is formed from lumber through a process described subsequently. Member 12 includes a stop region 20, which selectively engages the door and defines the forward limit to which the door may pivot in the direction of the exterior of the wall. Member 12 also defines a rabbetted or removed region 22 through which the door passes before and while in engagement with stop region 20.
Each jamb typically includes some form of weather stripping 24 that is secured to stop region 20. In FIG. 1, weather stripping 24 is inserted within a channel 26 carved within stop region 20. The jambs and header may also include brickmold, which is mounted on exterior surface 16 and extends laterally beyond the frame to overlap a portion of the exterior surface of the wall forming the opening for the frame. As shown in the portion of the lock-side jamb shown in FIG. 1, the jamb typically includes at least one socket within which portions of the door's lock are inserted to prevent selectively the door from being opened. As shown, jamb portion 10 includes a pair of sockets 28 and 29, which are configured to receive bolts from a standard door lock and a deadbolt lock.
While this configuration has been the industry standard for years and seems safe enough, it offers only minimal security to a determined intruder. The principle reason for this lack of security is due to the lumber which is used to form the conventional exterior door frame. Because sockets 28 and 29 are mounted a standardized distance away from stop member 20, there is only a narrow portion of base member 12 between the sockets and interior surface 18 of the jamb. Furthermore, because the grain of the lumber extends generally along the length of the jamb, the jamb is prone to splitting or shattering in the direction of the grain. These combined factors contribute to a frame which may be relatively easily broken or split by forcing, and most commonly kicking, the door inwardly in the general vicinity of where the lock engages the jamb's sockets.
Another problem with conventional exterior door frames is the way even treated lumber deteriorates when exposed to rain, extreme temperatures, snow, insects, etc., over a prolonged period of time. Wood exterior frames tend to splinter and chip over time, as well as when bumped or otherwise struck during use. Furthermore, when lumber gets wet, it expands. Therefore, conventional frames tend to deform and expand into the opening when water penetrates the weathertreating, if any, on the frame. Furthermore, once water contacts any portion of the lumber, it wicks along the wood to contact and thereby deform or begin deteriorating adjacent regions. Attempts have been made to wrap portions of the frames with a thin, paper-like layer of weather resistant material, but this has not proven to be a sufficient remedy for this problem over time. While this wrapping or capping process may extend the life of the frame, it still requires the time and labor-intensive process to form the underlying lumber construction, and furthermore lacks sufficient strength and structure to protect and support the rest of the frame. Therefore, there remains a need to protect a conventional frame from the elements, as well as from being struck by individuals or other objects.
An additional problem with conventional frames is the significant time-, labor- and waste-intensive steps needed to manufacture the frame. As an initial step, a tree is chopped down, delimbed, debarked and cut into elongate strips of lumber. During this initial step, approximately twenty-five percent, or more, of the original wood is wasted. The produced lumber predominately is what is referred to as "shop-grade" lumber, in that it is rough and contains knots and other irregularities. Therefore, the next step is to cut out the knots and other inregular areas from the lumber and then fingerjoint the remaining pieces back together. At this point, the lumber is in elongate lengths that are substantially free or "clear" of knots and other defects.
The lumber is next fed through a molder, which shapes the lumber into the cross-sectional configuration shown in FIG. 1. At this point, approximately forty or more percent of the remaining wood has been discarded or otherwise removed from the original lengths of lumber. Next, notches 26 are carved into the stop regions of the strips, the strips are cut to length and the ends are notched with a double end tenoner so that the jambs and header will smoothly mate with each other. The lengths of molded lumber are subsequently primed, so that they may be later painted, and weathertreated, to slow the deterioration of the frame from exposure to rain, snow and other elements. Finally, the frame is assembled, weather stripping is secured to the jambs, sockets are drilled in one jamb to receive portions of a lock, and a door is hung on the other jamb.
This process is not only slow and labor-intensive, but as discussed above, also is extremely wasteful, raising environmental as well as other cost and efficiency concerns. Although a number of exterior door frames are known in the prior art, such frames are unsatisfactory due to their failure to address and satisfy all of the concerns listed above.
With the above problems in mind, it is an object of the present invention to provide an exterior door frame that may be quickly and easily produced without the excessive waste, time and labor required to produce conventional frames.
Another object is to provide a maintenance free door frame that is durable and rugged enough to maintain its appearance and strength even after prolonged exposure to the elements.
One more object is to provide an exterior door frame that includes a structural shell that protects the core of the frame from damage and from exposure to the elements.
Yet another object is to provide such a shell that is snap-fit onto the frame's core.
Still another object is to provide such a shell that is waterproof and substantially free from holes or other apertures.
Another object is to provide such a shell that can be extruded in a continuous expanse.
One more object is to provide an exterior door frame with a core that is stronger and less prone to splitting when compared to lumber.
Another object is to provide such a core that is formed by discrete lengths of plywood.
Still another object is to provide such a core that may be formed from a cellulosic material.
Yet another object is to provide an exterior door frame that includes a brickmold member, and especially a brickmold member that can be snap-fit to the frame.
The invention achieves these and other objects and advantages in the form of a composite exterior door frame that includes a plurality of framing members, each including a core formed from a foamed or cellulosic material that includes a wall surface adapted to be mounted within a cavity formed in the wall of the house or other building with which the frame is to be used, and a door surface is opposed to the wall surface and is adapted to extend within the cavity. The core preferably includes an elongate base member and an elongate stop member mounted on the base member in a parallel relationship to the base member. Each framing member further includes a resilient shell, which is preferably formed from a waterproof material, and which may be snap-fit on the core. The shell forms a continuous waterproof expanse which generally conforms to the shape and configuration of the core to cover and protect the door surface of the core and the lateral edges extending between the core's wall surface and the door surface. The shell may further include weather stripping that is formed with the shell in a one-piece unit, and the framing members may further include conventional or invented brickmold attached thereto.
These and other advantages and features of the invention will become more fully apparent as the detailed description below is read with reference to the accompanying drawings.